Study estimates human metabolism produced 2.05 billion tonnes of CO2 in 2015
Written by AI from sciencedaily.com's report. Not checked by a person.
A University of Bath-led study estimates that CO2 from human metabolism rose 74% between 1985 and 2015, reaching 2.05 billion metric tons a year, mainly because of population growth.
Researchers led by Professor Javier Gonzalez of the University of Bath have estimated how much carbon dioxide people produce just by turning food into energy. Their study, published in The Lancet Planetary Health, calculates that global CO2 production from human metabolism rose from 1.18 billion metric tons in 1985 to 2.05 billion metric tons in 2015, an increase of 74%.
More than 60% of that rise was due to the growing number of people worldwide, while changes in how much CO2 each person produces played a much smaller role. To reach the estimate, the team analyzed thousands of measurements from people of all ages, from infants to older adults, and combined them with global population and body weight data.
The scientists stress that this CO2 differs from fossil fuel emissions. Most of the carbon people breathe out comes from food, and plants took it from the atmosphere relatively recently, so it is already part of the natural carbon cycle. Burning coal, oil and natural gas releases carbon that had been stored underground for millions of years.
Gonzalez said the study does not suggest that breathing is driving climate change, and the researchers are not recommending that people change their diets or activity levels. Instead, the figures should help scientists build more complete carbon budgets and more accurately predict how effective carbon reduction strategies will be.
